A/C Shutdown

D

Doc

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After my Cruisair SMX a/c runs for 24 or so hours it turns itself off. No fault code shows on the display. The only thing showing on the digital display is the set temperature. The second unit running at the same time is not affected. Same pump.

The manual mentions several fault codes but none show. The breaker is not thrown.

Ideas?
 
what do you have to do to restart it? Do you hit the power button to turn it off and then back on? Or can you just adjust the temp setting to get it to start?
 
Try switching control panels between the two units and see what happens.
 
Is it possible the one unit has become partially clogged? You might want to try back flushing both units with acid. The water temperatures are pretty warm. However if both units seem to be cooling like normal perhaps one unit is getting low on Freon? Which unit shuts off the one furthest from the circulation pump?
Bill
 
Digital display would show a high pressure error if it was an issue with growth or reduced flow.

I agree with bill! try swapping the displays although it could also be an issue with the electronic board on the unit, which is a little harder to swap.
 
To turn it back on I have to hit the cool button. Adjusting the thermostat up or down has no effect. It is like when you turn it off and only the temp shows.

Plenty of water flow. Both units use the same pump but each has its own over board discharge.

It has now run for 18 hours since the shutdown with no problems. This same thing happened once on my last week long trip.
 
quote:
Originally posted by Doc

To turn it back on I have to hit the cool button. Adjusting the thermostat up or down has no effect. It is like when you turn it off and only the temp shows.

Plenty of water flow. Both units use the same pump but each has its own over board discharge.

It has now run for 18 hours since the shutdown with no problems. This same thing happened once on my last week long trip.

Click to expand...
At this point it's sounds like the problem doesn't happen often enough to even speculate if there is a problem? It sounds like you are in the initial phase of a potential problem. I'd try cleaning the electrical connector or connections between the display/ controller and the main unit's PC Board. I'm not sure I'd swap anything out at this point.
Bill
 
Billy,

If you have ever tried to sleep on a hot boat in southwest Florida (with an 11 year old grandson aboard...and bored) you might not call it a non problem. ;-)

So, I am trying to find out what is going on.
 
quote:
Originally posted by Doc

To turn it back on I have to hit the cool button. Adjusting the thermostat up or down has no effect. It is like when you turn it off and only the temp shows.

Plenty of water flow. Both units use the same pump but each has its own over board discharge.

It has now run for 18 hours since the shutdown with no problems. This same thing happened once on my last week long trip.

Click to expand...
There is a thermal switch on the compressor that could cause this problem but it will normally throw a code? When the AC shut down the last time was the boat moving or tied to the dock? I assume everyone else on the dock is running their AC units? Do both your AC units run off the same AC Main or are they on separate AC mains?
Bill
 
Every issue that has been speculated on should throw a code on the display, if the logic board is working correctly. Inadequate flow or clogged coils will cause high head pressure and throw a HI-PS error on the display. Low coolant will cause the compressor to ice, low pressure and LO-PS display. AC voltage dipping would cause the unit to shut down with a LO-AC message.

I have a split gas system on my boat and just had one of the units fail due to what turned out to be a bad logic board. The failure manifested as the unit shutting down exactly as Doc describes, except mine would shut off after 1-15 seconds of the compressor running. The fix was replacing the logic board. Cost about $275 and was fixed in about half an hour. One word of caution, many of these units, mine included, are 240v. Make sure you turn off the power before cracking any of the covers, 240v shocks aren't quickly forgotten.

Ben
 
I agree unless the logic board won't allow a code to be displayed it could be the problem...
Bill
 
quote:
Originally posted by Billylll

I agree unless the logic board won't allow a code to be displayed it could be the problem...
Bill

Click to expand...


Yep, but even then the logic board needs replacing / repairing before you get to the next issue.

BTW, for those that ever have problems with either the logic board or the your thermostats Flight Systems will repair both. I bought a new logic board for about $275 but will send my failed one to them for repair so I have a spare on board. I believe it's about half the price of a new one.

Ben
 
Off topic but honestly I'm not sold on water heat/ cool exchanged systems like I once was. I'm trying a 14,000BTU self contained heat pump on the trawler. It supposed to cover up to 900 cubic feet and it draws <10amps it's also rated in tons 1.25 at 110VAC. It should by it's specifications heat down to -20 degrees "F". That's never going to happen with a conventional marine heat pump. The only negatives I see so far are it requires (2) 4" exhaust holes this will be on the port side above the deck on my Gulfstar. It also has a 1 gallon condensate tray, I plan on plumbing it directly over board or into my new Johnson shower sump.
Since it will be in the salon/ lower helm (raised area) the cold air should fall making cooling the bow and aft staterooms fairly easy with a few well placed 12 VDC turbo fans. What's the worst that can happen? I have 2 4" holes I'll need to re-glass that assumes it doesn't work at all. I think there are more positives than negatives and I will be happy to report my short term results cooling and long term results is it reliable and does the heat portion work 1/2 as good as advertised?
Bill
 
Bill,

I'll be very curious to hear how well that works out. When I first got into boating and looked at how marine AC systems worked (and are priced) I was very skeptical. I guess I've made my peace with the fact that the AC systems still seem like the simplest way out there to sink a boat. The part where a system that I leave on when not there (pretty much out of necessity) pulls water into the boat and then hopefully dumps it back overboard has never sat all that well with me.

Ben
 
Questions.....If he switches the T'stats and if the same unit shuts down, when the unit shuts down would the new T'stat show a fault code? Based on HaveADay's experience, if I read it right, the other unit should shut down if the T'stat is shot. Correct?
 
My experience was that the problem stayed with the unit. So, I swapped in a known good thermostat and the same location (with the now known good thermostat) continued to experience issues. This made sense as the problem was actually the control board in the unit, not the thermostat. So, based on that I wouldn't expect any difference in what's displayed based on the thermostat.

It's also worth noting that what we all call thermostats really aren't. They're basically just remote displays with buttons. The intelligence is in the control board in the unit. There's no temperature sensor in the thermostat and it's not calling for heat or cooling. It's just telling the logic board in the unit that the user would like to change the set point from one value to another or change the mode, fan speed, etc.

Ben
 
All good ideas. Thanks.

Now tell me what to do with an 11 year old boy that we took for a week to a world class resort...South Seas Island Resort on Captive Island... that says he is bored by every activity they have here?
 
quote:
Originally posted by Doc

All good ideas. Thanks.

Now tell me what to do with an 11 year old boy that we took for a week to a world class resort...South Seas Island Resort on Captive Island... that says he is bored by every activity they have here?

Click to expand...


granny.jpg


Spare the rod and spoil the child!
 
quote:
Originally posted by Doc

All good ideas. Thanks.

Now tell me what to do with an 11 year old boy that we took for a week to a world class resort...South Seas Island Resort on Captive Island... that says he is bored by every activity they have here?

Click to expand...


Better yet, get him an 11 year old girl or a school teacher.
 
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